package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;


/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Autowired
    private ISeckillVoucherService seckillVoucherService;

    @Autowired
    private RedisIdWorker redisIdWorker;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 * 1024);

    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init() {
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        String queueName = "stream.orders";

        @Override
        public void run() {
            while (true) {
                try {
                    //1.获取消息队列的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 STREAMS stream.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed()));
                    //2.判断消息是否获取成功
                    if(list == null || list.isEmpty()){
                        //2.1 获取失败说明没有消息，进行下一次循环
                        continue;
                    }
                    //3.解析消息中的订单信息
                    MapRecord<String, Object, Object> msgInfos = list.get(0);
                    //存放在消息队列中的键值对信息
                    Map<Object, Object> values = msgInfos.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //3.1 获取成功，创建订单
                    handleVoucherOrder(voucherOrder);
                    //4.ack确认消息 XACK stream.order g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",msgInfos.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

        /**
         * 处理pending-list消息
         */
        private void handlePendingList() {
            while (true) {
                try {
                    //1.获取消息队列的订单信息 XREADGROUP GROUP g1 c1 COUNT 1  STREAMS stream.order 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0")));
                    //2.判断消息是否获取成功
                    if(list == null || list.isEmpty()){
                        //2.1 获取失败，说明pending-list没有消息，跳出循环
                        break;
                    }
                    //3.解析消息中的订单信息
                    MapRecord<String, Object, Object> msgInfos = list.get(0);
                    //存放在消息队列中的键值对信息
                    Map<Object, Object> values = msgInfos.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values, new VoucherOrder(), true);
                    //3.1 获取成功，创建订单
                    handleVoucherOrder(voucherOrder);
                    //4.ack确认消息 XACK stream.order g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",msgInfos.getId());
                } catch (Exception e) {
                    log.error("处理pending-list异常", e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        ex.printStackTrace();
                    }
                }
            }
        }
    /*private class VoucherOrderHandler implements Runnable {

        @Override
        public void run() {
            while (true) {
                try {
                    //获取阻塞队列的订单信息
                    VoucherOrder order = orderTasks.take();
                    //创建订单
                    handleVoucherOrder(order);
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                }
            }
        }*/

        private void handleVoucherOrder(VoucherOrder voucherOrder) {
            Long userId = voucherOrder.getUserId();
            //创建锁对象
//        SimpleRedisLock simpleRedisLock = new SimpleRedisLock(stringRedisTemplate, "order:" + userId);
//        boolean isLock = simpleRedisLock.tryLock(1200L);
            RLock lock = redissonClient.getLock("lock:order:" + userId);
            boolean isLock = lock.tryLock();
            //判断是否获取锁成功
            if (!isLock) {
                //获取锁失败，返回错误或重试
                log.error("不允许重复下单");
                return;
            }
            try {
                proxy.createVoucherOrder(voucherOrder);
            } finally {
                lock.unlock();
            }

        }
    }

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("/lua/seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        //执行lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(), voucherId.toString(), userId.toString(), String.valueOf(orderId));
        //判断结果为0
        int r = result.intValue();
        if (r != 0) {
            //不是0，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //返回信息
        return Result.ok(orderId);
    }

    /*@Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisIdWorker.nextId("order");
        //执行lua脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(), voucherId.toString(), userId.toString(), String.valueOf(orderId));
        //判断结果为0
        int r = result.intValue();
        if (r != 0) {
            //不是0，代表没有购买资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }
        //为0 有购买资格，把下单信息保存到阻塞队列
        VoucherOrder voucherOrder = new VoucherOrder();
        voucherOrder.setId(orderId);
        voucherOrder.setVoucherId(voucherId);
        voucherOrder.setUserId(userId);
        // 保存阻塞队列
        orderTasks.add(voucherOrder);
        //获取代理对象（事务）
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //返回信息
        return Result.ok(orderId);
    }*/

    /**
     * java代码实现秒杀优惠券，创建订单业务
     *
     * @param voucherOrder
     */
    /*@Override
    public Result seckillVoucheer(Long voucherId) {
        //1.查询优惠券
        SeckillVoucher seckillVoucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否开始
        if (seckillVoucher.getBeginTime().isAfter(LocalDateTime.now())) {
            return Result.fail("秒杀未开始");
        }
        if (seckillVoucher.getEndTime().isBefore(LocalDateTime.now())) {
            return Result.fail("秒杀已结束");
        }
        if (seckillVoucher.getStock() < 1) {
            return Result.fail("库存不足");
        }
        Long userId = UserHolder.getUser().getId();
        //创建锁对象
//        SimpleRedisLock simpleRedisLock = new SimpleRedisLock(stringRedisTemplate, "order:" + userId);
//        boolean isLock = simpleRedisLock.tryLock(1200L);
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        //判断是否获取锁成功
        if(!isLock){
            //获取锁失败，返回错误或重试
            return Result.fail("不允许重复下单");
        }
        try {
            //获取代理对象（事务）
            IVoucherOrderService orderService = (IVoucherOrderService) AopContext.currentProxy();
            return orderService.createVoucherOrder(voucherId);
        }finally {
            lock.unlock();
        }

    }*/
    @Override
    @Transactional(rollbackFor = Exception.class)
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();
        //查询订单
        Long count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count > 0) {
            log.error("请勿重复下单");
            return;
        }
        //扣减库存
        boolean success = seckillVoucherService.update().setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0).update();
        if (!success) {
            log.error("库存不足");
            return;
        }
        //创建订单
        save(voucherOrder);
    }
}
